[FFmpeg-devel] [PATCH] avcodec/videotoolboxenc: add low-latency encoding

[xufuji456]

When using low-latency mode, it eliminates frame reordering
and follows a one-in-one-out encoding mode

Signed-off-by: xufuji456 <839789740 at qq.com>
---
 libavcodec/videotoolboxenc.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
index c6f22723d6..ae1ef32b2d 100644
--- a/libavcodec/videotoolboxenc.c
+++ b/libavcodec/videotoolboxenc.c
@@ -1441,6 +1441,17 @@ static int vtenc_create_encoder(AVCodecContext   *avctx,
         }
     }
 
+    // low-latency mode: eliminate frame reordering, follow a one-in-one-out encoding mode
+    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && avctx->codec_id == AV_CODEC_ID_H264) {
+        status = VTSessionSetProperty(vtctx->session,
+                                      kVTVideoEncoderSpecification_EnableLowLatencyRateControl,
+                                      kCFBooleanTrue);
+
+        if (status) {
+            av_log(avctx, AV_LOG_ERROR, "Error setting low latency property: %d\n", status);
+        }
+    }
+
     status = VTCompressionSessionPrepareToEncodeFrames(vtctx->session);
     if (status) {
         av_log(avctx, AV_LOG_ERROR, "Error: cannot prepare encoder: %d\n", status);
-- 
2.32.0 (Apple Git-132)